Abstract
BackgroundLoss of Amylo-alpha-1-6-glucosidase-4-alpha-glucanotransferase (AGL) drives rapid proliferation of bladder cancer cells by upregulating Hyaluronic acid(HA) Synthase (HAS2) mediated HA synthesis. However the role of HA receptors CD44 and Hyaluronan Mediated Motility Receptor (RHAMM) in regulating the growth of bladder cancer cells driven by loss of AGL has not been studied.MethodsWestern blot analysis and Terminal deoxynucleotidyl transferase (TdT) dUTP Nick-End Labeling (TUNEL) assay was carried out to study cellular apoptosis with HAS2, CD44 and RHAMM loss in bladder cancer cells with and without AGL expression. Proliferation and softagar assays were carried out to study cellular anchorage dependent and independent growth. Clinicopathologic analysis was carried out on bladder cancer patient datasets.ResultsHigher amounts of cleaved Cas3, Cas9 and PARP was observed in AGL low bladder cancer cell with loss of HAS2, CD44 or RHAMM. TUNEL staining showed more apoptotic cells with loss of HAS2, CD44 or RHAMM in AGL low bladder cancer cells. This revealed that bladder cancer cells whose aggressive growth is mediated by loss of AGL are susceptible to apoptosis with loss of HAS2, CD44 or RHAMM. Interestingly loss of either CD44 or RHAMM induces apoptosis in different low AGL expressing bladder cancer cell lines. Growth assays showed that loss of CD44 and RHAMM predominantly inhibit anchorage dependent and independent growth of AGL low bladder cancer cells. Clinicopathologic analysis revealed that high RHAMM mRNA expression is a marker of poor patient outcome in bladder cancer and patients with high RHAMM and low AGL tumor mRNA expression have poor survival.ConclusionOur findings strongly point to the importance of the HAS2-HA-CD44/RHAMM pathway for rapid growth of bladder cancer cells with loss of AGL and provides rational for targeting this pathway at various steps for “personalized” treatment of bladder cancer patients based of their AGL expression status.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-016-2756-5) contains supplementary material, which is available to authorized users.
Highlights
Loss of Amylo-alpha-1-6-glucosidase-4-alpha-glucanotransferase (AGL) drives rapid proliferation of bladder cancer cells by upregulating Hyaluronic acid(HA) Synthase (HAS2) mediated Hyaluronic Acid (HA) synthesis
Earlier studies have shown that inhibition of HA synthesis results in reduction of CD44 and Hyaluronan mediated motility receptor (RHAMM) expression, and leads to cellular apoptosis [13, 14]
We have earlier shown that loss of AGL induces rapid growth of bladder cancer cells via Hyaluronic acid synthase 2 (HAS2) mediated HA synthesis [5]
Summary
Loss of Amylo-alpha-1-6-glucosidase-4-alpha-glucanotransferase (AGL) drives rapid proliferation of bladder cancer cells by upregulating Hyaluronic acid(HA) Synthase (HAS2) mediated HA synthesis. The role of HA receptors CD44 and Hyaluronan Mediated Motility Receptor (RHAMM) in regulating the growth of bladder cancer cells driven by loss of AGL has not been studied. Amylo-alpha-1-6-glucosidase-4-alpha-glucanotransferase (AGL) and glycogen phosphorylase (PYG) isoforms are responsible for glycogen breakdown (glycogenolysis) in humans [1]. We have identified AGL as a tumor growth suppressor and prognostic marker in human bladder cancer, for the first time showing AGL plays a role in cancer biology [4]. We have further identified that loss of AGL promotes rapid cancer cell proliferation dependent on extracellular glucose, Serine Hydroxymethyltransferase 2 (SHMT2) driven glycine synthesis and Hyaluronic Acid (HA) Synthase 2 (HAS2) mediated HA synthesis [4, 5]. Using genetic manipulation and chemical inhibition of HA synthesis we have demonstrated that HAS2 dependent HA synthesis is a major driven of tumor growth with AGL loss [5]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
